Molecular viscosity and diffusivity effects in transitional and shock-driven mixing flows.

This paper investigates the importance of molecular viscosity and diffusivity for the prediction of transitional and shock-driven mixing flows featuring high and low Reynolds and Mach number regions. Two representative problems are computed with implicit large-eddy simulations using the inviscid Euler equations (EE) and viscous Navier-Stokes equations (NSE): the Taylor-Green vortex at Reynolds number Re=3000 and initial Mach number Ma=0.28, and an air-SF_{6}-air gas curtain subjected to two shock waves at Ma=1.2. The primary focus is on differences between NSE and EE predictions due to viscous effects. The outcome of the paper illustrates the advantages of utilizing NSE. In contrast to the EE, where the effective viscosity decreases upon grid refinement, NSE predictions can be assessed for simulations of flows with transition to turbulence at prescribed constant Re. The NSE can achieve better agreement between solutions and reference data, and the results converge upon grid refinement. On the other hand, the EE predictions do not converge with grid refinement, and can only exhibit similarities with the NSE results at coarse grid resolutions. We also investigate the effect of viscous effects on the dynamics of the coherent and turbulent fields, as well as on the mechanisms contributing to the production and diffusion of vorticity. The results show that nominally inviscid calculations can exhibit significantly varying flow dynamics driven by changing effective resolution-dependent Reynolds number, and highlight the role of viscous processes affecting the vorticity field. These tendencies become more pronounced upon grid refinement. The discussion of the results concludes with the assessment of the computational cost of inviscid and viscous computations.

Chronic osteomyelitis in canine penile bone: case report / Osteomielite crônica em osso peniano canino: relato de caso

A 10-year-old male mixed-breed dog was admitted for recurrent signs of urinary tract infection (UTI). Urinary bladder ultrasonography revealed decreased thickness of its wall with floating hyperopic particles within its lumen. Ultrasonography revealed a structure invading the dorsal wall of the penile urethral lumen, located in a segment distal to the bladder. Radiographies showed bone resorption with proliferation at the caudal aspect of the penile bone, stricture of the final aspect of the penile urethra, and no radiopaque images compatible with a urethrolith. Computed tomography showed bone proliferation causing stricture of the urethral lumen at two different sites. Presumptive diagnosis of penile neoplasia was considered more likely and the dog underwent penectomy along with orchiectomy and scrotal urethrostomy. Enterobacter spp. was cultured from the urine sample and antibiotic sensitivity tests revealed that the bacterium was susceptible to amikacin, imipenem, and meropenem. Histopathology revealed severe suppurative urethritis, bone resorption, and hyperostosis, suggestive of osteomyelitis of the penile bone. Neoplastic cells were not observed at any part of the examined tissue. The findings in the present case suggest that osteomyelitis of the penile bone should be included in differential diagnosis for partial and complete urethral obstruction in dogs with recurrent UTI.(AU)

Um cão mestiço, com 10 anos, foi admitido por sinais recorrentes de infecção do trato urinário (ITU). A ultrassonografia da bexiga urinária revelou diminuição da espessura de sua parede com partículas flutuantes dentro de seu lúmen. A ultrassonografia demonstrou estrutura invadindo a parede dorsal do lúmen da uretra peniana, localizada em segmento distal à bexiga. Radiografias evidenciaram reabsorção óssea com proliferação no aspecto caudal do osso peniano, estenose do aspecto final da uretra peniana e ausência de imagens radiopacas compatíveis com uretrólito. Pela tomografia computadorizada, observou-se proliferação óssea causando estreitamento da luz uretral em dois locais diferentes. Diagnóstico presuntivo de neoplasia peniana foi considerado mais provável e o cão foi submetido à penectomia, juntamente com orquiectomia e uretrostomia escrotal. Enterobacter spp. foi cultivada da amostra de urina e testes de sensibilidade revelaram susceptibilidade ao amicacina, imipenem e ao meropenem. A histopatologia revelou uretrite supurativa grave, reabsorção óssea e hiperostose compatível com osteomielite do osso peniano. Células neoplásicas não foram observadas em nenhuma parte do tecido examinado. Os achados do presente caso sugerem que a osteomielite do osso peniano deve ser incluída no diagnóstico diferencial de obstrução uretral parcial e completa em cães com ITU recorrente.(AU)

Executive dysfunction correlates with impaired functional status in older adults with varying degrees of cognitive impairment.

BACKGROUND: Previous studies have reported an association between executive dysfunction and the ability to perform activities of daily living (ADL)s among older adults. This study aims to examine the association between executive functions and functional status in a cross-section of older adults with varying degrees of cognitive impairment. METHODS: 89 individuals (mean age 73.8 years) were recruited at a memory clinic in São Paulo, Brazil. Subjects underwent evaluation, and were allocated into three diagnostic groups according to cognitive status: normal controls (NC, n = 32), mild cognitive impairment (MCI, n = 31) and mild Alzheimer's disease (AD, n = 26). Executive functions were assessed with the 25-item Executive Interview (EXIT25), and functional status was measured with the Direct Assessment of Functional Status test (DAFS-R). RESULTS: Significantly different total DAFS-R scores were observed across the three diagnostic groups. Patients with AD performed significantly worse in EXIT25 compared with subjects without dementia, and no significant differences were detected between NC and MCI patients. We found a robust negative correlation between the DAFS-R and the EXIT25 scores (r =-0.872, p < 0.001). Linear regression analyses suggested a significant influence of the EXIT-25 and the CAMCOG on the DAFS-R scores. CONCLUSION: Executive dysfunction and decline in general measures of cognitive functioning are associated with a lower ability to undertake instrumental ADLs. MCI patients showed worse functional status than NC subjects. MCI patients may show subtle changes in functional status that may only be captured by objective measures of ADLs.

Genomic analysis of Brazilian patients with Fabry disease

Fabry disease is an X-linked lysosomal disorder due to a-galactosidase A deficiency that causes storage of globotriaosylceramide. The gene coding for this lysosomal enzyme is located on the long arm of the X chromosome, in region Xq21.33-Xq22. Disease progression leads to vascular disease secondary to involvement of kidney, heart and the central nervous system. Detection of female carriers based solely on enzyme assays is often inconclusive. Therefore, mutation analysis is a valuable tool for diagnosis and genetic counseling. Many mutations of the a-galactosidase A gene have been reported with high genetic heterogeneity, being most mutations private found in only one family. The disease is panethnic, and estimates of incidence range from about 1 in 40,000 to 60,000 males. Our objective was to describe the analysis of 6 male and 7 female individuals belonging to 4 different Fabry disease families by automated sequencing of the seven exons of the a-galactosidase gene. Sequencing was performed using PCR fragments for each exon amplified from DNA extracted from peripheral blood. Three known mutations and one previously described in another Brazilian family were detected. Of 7 female relatives studied, 4 were carriers. Although the present study confirms the heterogeneity of mutations in Fabry disease, the finding of the same mutation previously detected in another Fabry family from our region raises the possibility of some founder effect, or genetic drift. Finally, the present study highlights the importance of molecular analysis for carrier detection and genetic counseling.

Genomic analysis of Brazilian patients with Fabry disease.

Fabry disease is an X-linked lysosomal disorder due to a-galactosidase A deficiency that causes storage of globotriaosylceramide. The gene coding for this lysosomal enzyme is located on the long arm of the X chromosome, in region Xq21.33-Xq22. Disease progression leads to vascular disease secondary to involvement of kidney, heart and the central nervous system. Detection of female carriers based solely on enzyme assays is often inconclusive. Therefore, mutation analysis is a valuable tool for diagnosis and genetic counseling. Many mutations of the a-galactosidase A gene have been reported with high genetic heterogeneity, being most mutations private found in only one family. The disease is panethnic, and estimates of incidence range from about 1 in 40,000 to 60,000 males. Our objective was to describe the analysis of 6 male and 7 female individuals belonging to 4 different Fabry disease families by automated sequencing of the seven exons of the alpha-galactosidase gene. Sequencing was performed using PCR fragments for each exon amplified from DNA extracted from peripheral blood. Three known mutations and one previously described in another Brazilian family were detected. Of 7 female relatives studied, 4 were carriers. Although the present study confirms the heterogeneity of mutations in Fabry disease, the finding of the same mutation previously detected in another Fabry family from our region raises the possibility of some founder effect, or genetic drift. Finally, the present study highlights the importance of molecular analysis for carrier detection and genetic counseling.

An ab-initio study of the C3H6-HX, C2H4-HX and C2H2-HX hydrogen-bonded complexes with X=F or Cl.

MP2/6-31G** ab-initio molecular orbital calculations have been performed to obtain geometries, H-bond energies and vibrational properties of the C3H6-HX, C2H4-HX and C2H2-HX H-bonded complexes with X=F or Cl. The more pronounced effects on the structural parameters of the isolated molecules due to complexation are verified to the CC and HX bond lengths, which are directly involved in the H-bond formation. They are increased after complexation. The calculated H-bond lengths for the hydrogen complexes for X=F are shorter than those for x-Cl by about 0.55 A, whereas the corresponding experimental value is 0.58 A. The H-bond energies are essentially determined by the nature of the proton donor molecule. For X=F, the AE mean value is 20 kJ/mol, whereas it is approximately 14.5 kJ/mol for X-Cl. The H-bond energies including zero-point corrections show a good correlation with the H-bond lengths. The more pronounced effect on the normal modes of the isolated molecules after complexation occurs to the H-X stretching mode. The H-X stretching frequency is shifted downward, whereas its IR intensity is much enhanced upon H-bond formation. The new vibrational modes arising from complexation show several interesting features.

[The rare metastasis of osteosarcoma of a long bone associated with von Recklinghausen's neurofibromatosis]. / Metastatização rara de osteossarcoma de um osso longo associado a neurofibromatose de von Recklinghausen.

We report a case of femoral osteosarcoma with brain metastases in a female patient with longstanding von Recklinghausen disease. Osteosarcoma of a long bone has not yet, to our best knowledge, been reported in association with type I Neurofibromatosis. Central nervous system metastases occur very rarely in osteosarcoma.